title: Comparison of the prevalence of common bacterial pathogens in the oropharynx and nasopharynx of gambian infants.
abstract: BACKGROUND
  CRM- based pneumococcal conjugate vaccines generally have little impact on the overall prevalence of pneumococcal carriage because of serotype replacement. In contrast, protein vaccines could substantially reduce the overall prevalence of pneumococcal carriage with potential microbiological and clinical consequences. Therefore, trials of pneumococcal protein vaccines need to evaluate their impact on carriage of other potentially pathogenic bacteria in addition to the pneumococcus.
  
  
  METHODS
  As a prelude to a trial of an investigational pneumococcal vaccine containing pneumococcal polysaccharide conjugates and pneumococcal proteins, the prevalence of carriage of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella species and Staphylococcus aureus in the nasopharynx of 1030 Gambian infants (median age 35 weeks) was determined. An oropharyngeal swab was obtained at the same time from the first 371 infants enrolled. Standard microbiological techniques were used to evaluate the bacterial flora of the pharynx and to compare that found in the oropharynx and in the nasopharynx.
  
  
  RESULTS
  The overall pneumococcal carriage rate was high. Isolation rates of S. pneumoniae and Moraxella species were significantly higher using nasopharyngeal rather than oropharyngeal swabs (76.1% [95% CI 73.4%,78.7%] vs. 21.3% [95% CI 17.2%,25.8%] and 48.9% [95% CI 45.8%, 52.0%] vs. 20.5% % [95% CI 16.5%,25.0%] respectively). In contrast, S. aureus and H. influenzae were isolated more frequently from oropharyngeal than from nasopharyngeal swabs (65.0% [95% CI 59.9%, 69.8%] vs. 33.6% [95% CI 30.7%, 36.5%] and 31.8% [95% CI 16.5%, 25.0%] vs. 22.4% [95% CI 19.9%, 25.1%] respectively). No group A β haemolytic streptococci were isolated.
  
  
  CONCLUSIONS
  Collection of an oropharyngeal swab in addition to a nasopharyngeal swab will provide little additional information on the impact of a novel pneumococcal vaccine on pneumococcal carriage but it might provide additional, valuable information on the impact of the vaccine on the overall microbiota of the pharynx.
authors.affiliation: Vaccinology Theme, Medical Research Council Unit, Banjul, The Gambia.
authors.forename: Aderonke
authors.initials: A
authors.lastname: Odutola
authors.forename: Martin
authors.initials: M
authors.lastname: Antonio
authors.forename: Olumuyiwa
authors.initials: O
authors.lastname: Owolabi
authors.forename: Abdoulie
authors.initials: A
authors.lastname: Bojang
authors.forename: Ebenezer
authors.initials: E
authors.lastname: Foster-Nyarko
authors.forename: Simon
authors.initials: S
authors.lastname: Donkor
authors.forename: Ifedayo
authors.initials: I
authors.lastname: Adetifa
authors.forename: Sylvia
authors.initials: S
authors.lastname: Taylor
authors.forename: Christian
authors.initials: C
authors.lastname: Bottomley
authors.forename: Brian
authors.initials: B
authors.lastname: Greenwood
authors.forename: Martin
authors.initials: M
authors.lastname: Ota
mesh_terms: D001426:Bacterial Proteins / Q000276:immunology; D005260:Female; D006192:Haemophilus Infections / Q000276:immunology / Q000517:prevention & control; D006193:Haemophilus influenzae / Q000276:immunology; D006801:Humans; D007223:Infant; D008297:Male; D009016:Moraxella / Q000276:immunology; D045828:Moraxellaceae Infections / Q000276:immunology / Q000517:prevention & control; D009305:Nasopharynx / Q000276:immunology / Q000382:microbiology*; D009960:Oropharynx / Q000276:immunology / Q000382:microbiology*; D011008:Pneumococcal Infections / Q000276:immunology / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000276:immunology; D015995:Prevalence; D013203:Staphylococcal Infections / Q000276:immunology / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000276:immunology; D013296:Streptococcus pneumoniae / Q000276:immunology; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate